1. Field of the Invention
The invention relates to a tie or anchoring arrangement assembled in situ to anchor an upper framed portion of a building structure to a lower masonry wall portion
2. Background Information
Concrete masonry walls can be formed of vertically stacked concrete blocks having internal, vertical, mutually aligned cavities that form channels extending vertically through the wall. These may be reinforced by placing rebar through the vertically aligned cavities and filling the channels about the bars with a wet cementitious mixture known as grout. The grout, when set, locks the bars to the blocks and thus provides the wall with increased resistance to applied loads.
Frame structures are often erected on top of reinforced or non-reinforced masonry walls. These may be roofs, wooden frame portions of composite walls, or a combination of a framed upper wall and a roof. Composite walls having a framed upper portion are popular in the construction of multi-story, multi-family residential buildings. The upper frame portion of the overall structure may be constructed in situ at the job site, may be prefabricated off site, or may be assembled on-site from prefabricated components (e.g., the combination of a prefabricated wall and a roof formed from prefabricated trusses). Regardless of the exact nature of its construction, the frame portion of such a structure is preferably firmly connected to the underlying masonry wall. In many locales, where hurricanes and other windstorms are a concern, building codes mandate that framework above a masonry wall be tied to the underlying wall by means suitable to withstand a substantial vertical force, as is expected from hurricane force winds.
One method for anchoring structural framework to the top of a masonry wall involves embedding anchors having threaded upper end portions into grout filling the vertical channels. Each of these anchors is preferably emplaced so that its shank and threaded upper end portions are vertical. Moreover, the anchors are set at pre-selected positions along the wall that accord with mating holes drilled through or otherwise formed in a sill plate or other lowermost portion of the framework. An initial step in erecting the framework may then consist of placing the lowermost piece of a wall frame over the protruding anchors, placing suitable washers and nuts on the threaded shafts of the anchors and turning the nuts to attach those two portions of the composite structure together.
This method relies on anchors being reliably emplaced in vertical settings at pre-selected positions along the wall. If an anchor is tilted or displaced from its predetermined position, erection of the framework will be delayed until that anchor is cut off and possibly replaced. Unfortunately, the prior art does not provide a reliable means for emplacing an entire array of anchors along a wall. If anchors are emplaced by being manually inserted into wet, unset grout, some of those anchors may fall over into unacceptable orientations as the grout sets. If anchors are vertically suspended from wire hangers prior to pouring the grout, some fraction of the anchors are often accidentally moved from their desired locations during grouting.
Queen, in U.S. Pat. No. 6,571,526, teaches apparatus for setting a reinforcing rod at a preselected position within a vertical channel in a concrete masonry wall. His devices generally provide a vertically extensive support for the rod at the top of a channel. Queen's devices, however, all extend downward an appreciable distance from the top of a block into the vertical channel. While this may be acceptable for setting the position and vertical orientation of a long rebar that extends the full height of the wall, it is unacceptable for embedding relatively short anchors at the top of the wall. Because his plastic device remains in the grout, Queen's approach would seriously degrade a short anchor's ability to withstand the vertical hold-down force specified by building codes.